1 /* 2 * Copyright (c) 1998, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 import static java.math.BigInteger.ONE; 25 26 import java.math.BigInteger; 27 import java.util.ArrayList; 28 import java.util.Arrays; 29 import java.util.Collections; 30 import java.util.List; 31 import java.util.Random; 32 33 /** 34 * @test 35 * @bug 7131192 36 * @summary This test ensures that BigInteger.floatValue() and 37 * BigInteger.doubleValue() behave correctly. 38 * @author Louis Wasserman 39 */ 40 public class PrimitiveConversionTests { 41 static final List<BigInteger> ALL_BIGINTEGER_CANDIDATES; 42 43 static { 44 List<BigInteger> samples = new ArrayList<>(); 45 // Now add values near 2^N for lots of values of N. 46 for (int exponent : Arrays.asList(0, 1, 2, 3, 4, 5, 6, 7, 31, 32, 33, 47 34, 62, 63, 64, 65, 71, 72, 73, 79, 80, 81, 255, 256, 257, 511, 48 512, 513, Double.MAX_EXPONENT - 1, Double.MAX_EXPONENT, 49 Double.MAX_EXPONENT + 1, 2000, 2001, 2002)) { 50 BigInteger x = ONE.shiftLeft(exponent); 51 for (BigInteger y : Arrays.asList(x, x.add(ONE), x.subtract(ONE))) { 52 samples.add(y); y.negate()53 samples.add(y.negate()); 54 } 55 } 56 57 Random rng = new Random(1234567); 58 for (int i = 0; i < 2000; i++) { samples.add(new BigInteger(rng.nextInt(2000), rng))59 samples.add(new BigInteger(rng.nextInt(2000), rng)); 60 } 61 62 ALL_BIGINTEGER_CANDIDATES = Collections.unmodifiableList(samples); 63 } 64 testDoubleValue()65 public static int testDoubleValue() { 66 int failures = 0; 67 for (BigInteger big : ALL_BIGINTEGER_CANDIDATES) { 68 double expected = Double.parseDouble(big.toString()); 69 double actual = big.doubleValue(); 70 71 // should be bitwise identical 72 if (Double.doubleToRawLongBits(expected) != Double 73 .doubleToRawLongBits(actual)) { 74 System.out.println(big); 75 failures++; 76 } 77 } 78 return failures; 79 } 80 testFloatValue()81 public static int testFloatValue() { 82 int failures = 0; 83 for (BigInteger big : ALL_BIGINTEGER_CANDIDATES) { 84 float expected = Float.parseFloat(big.toString()); 85 float actual = big.floatValue(); 86 87 // should be bitwise identical 88 if (Float.floatToRawIntBits(expected) != Float 89 .floatToRawIntBits(actual)) { 90 System.out.println(big + " " + expected + " " + actual); 91 failures++; 92 } 93 } 94 return failures; 95 } 96 main(String[] args)97 public static void main(String[] args) { 98 int failures = testDoubleValue(); 99 failures += testFloatValue(); 100 if (failures > 0) { 101 throw new RuntimeException("Incurred " + failures 102 + " failures while testing primitive conversions."); 103 } 104 } 105 } 106